[NSRCA-discussion] Looking For Props & Header

mjfrederick at cox.net mjfrederick at cox.net
Thu Nov 5 07:52:27 AKST 2009



I ran an NMP header on a 140 DZ for a couple years with no issues 
whatsoever. As most people are aware, the 140 DZ had some of the 
toughest vibration to tame of any of the YS engines. Here's what I did 
(no, I did not use any Permatex): Install one extra copper gasket (I had 
heard the issue may have been with the threaded piece bottoming out in 
the engine head), and I also re-tightened the header as tight as I 
possibly could after getting the engine up to running temp (something to 
do with differential expansion of all the different metals used to mount 
the headers). I never once had the header come loose, even when the 
Genesis did a triple lindy into the base of a huge oak tree. The head 
wasn't atached to the engine anymore, but I'll be damned if that NMP 
header wasn't as tight as ever (twisted, but still tight).

Matt

On Thu, Nov 5, 2009 at 7:54 AM, Bill Glaze wrote:

  In my case, it's a fairly simple problem.  The  1.40L vibrates so 
much, that the stud unscrews from the head, leaving the header  dangling 
in space alongside the exhaust port.  I have about a foot of  Teflon 
tubing between the outlet of the header, and the inlet of the Hatori 
pipe. I also have their (NMP) header brace in place to try to help 
stabilize the header.
The engine has already, after about 6 flights,  broken a Johnson Header; 
that's why I am trying the NMP.  I got the last  NMP Central had in 
stock, and they said that the person who was making them is  not doing 
so any more. (That's what I was told, anyway.)   The  Hatori pipe is 
sitting on one mount, about halfway back on the pipe, and the  whole 
outfit is free to move back and forth along with the engine  movement. 
I had hoped that, with the entire mess moving, it would permit  the stud 
to stay screwed in the head.  I'm worried lest the stud strip the 
threads in the head.  The instructions say that "some people have had 
the  header loosen" and to try a certain type of Permatex form-a-gasket 
material.  I've used this stuff before when I had a racing engine 
business,  but I certainly never used it in this type of application.
It seems to me that the entire problem is caused by  the excessive 
engine vibration that the 1.40L is known for.
Any help?
Bill Glaze
----- Original Message -----
 From: Troy Newman <mailto:troy at troynewman.net> 
<mailto:troy at troynewman.net>
To: General pattern discussion <mailto:nsrca-discussion at lists.nsrca.org> 
<mailto:nsrca-discussion at lists.nsrca.org>
Sent: Wednesday, November 04, 2009 5:39    PM 
<mailto:nsrca-discussion at lists.nsrca.org>
Subject: Re: [NSRCA-discussion] Looking    For Props & Header 
<mailto:nsrca-discussion at lists.nsrca.org>

  <mailto:nsrca-discussion at lists.nsrca.org>
I    don’t know what you mean by will it stay attached? 
<mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
The    new header is a wrap around style header like the previous NMP 
and the Hatori    822 style headers. 
<mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
All    of the 120-170 engines have the same head configuration (meaning 
same angle)     and same thread size. SO the new header will fit all 
120-170    engines.  <mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
There    is one exception. The 120AC has the air box on the back of the 
head. This    prevents the use of the wrap around style headers on this 
engine. Other than    that they are all the same. 
<mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
The    NMP header was a really good header for the application. When we 
were using    Teflon tubing to connect the header to the pipe it was 
excellent. The problem    was Hatori went to the newer style pipes that 
the header slides inside of the    neck of the pipe with the o-ring. The 
aluminum tubing used on the NMP header    was not as bullet proof in 
this application. Remember the Teflon when hot    would flex. Now the 
header and the pipe are attached to each other. The header    slides 
inside the pipe and the result is there is still movement but the 
stress on the thin wall aluminum piping is higher. Breaking, and the 
header    would get a grove worn in it. Actually the o-ring would pinch 
the aluminum    tubing to a smaller diameter and the header-pipe combo 
would leak. The added    stress of vibration and the direct connection 
many folks would break the    header tubing. 
<mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
The    new header is similar to the Hatori in terms of connection to the 
pipe. So    that swedging ( shrinking of the dia at the o-ring)  problem 
and the    leaking should be solved. In my setup its working well on the 
proto-type    headers. Next issue is the tubing being stronger to take 
the stress of the    direct connection. The solution is kind of unique 
and is working well. Some    more testing and maybe a few tweaks and its 
going to be a very good    replacement for the Hatori 822 and 823. 
<mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
Troy  <mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
 From: nsrca-discussion-bounces at lists.nsrca.org 
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Bill 
Glaze
Sent: Wednesday, November 04, 2009 9:05 AM
To: General pattern discussion
Subject: Re: [NSRCA-discussion] Looking    For Props & Header 
<mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
Troy:  <mailto:nsrca-discussion at lists.nsrca.org>
Will the new header    stay attached to the 1.40 L? Bill Glaze 
<mailto:nsrca-discussion at lists.nsrca.org>
----- Original      Message ----- 
<mailto:nsrca-discussion at lists.nsrca.org>
 From: Troy Newman <mailto:troy at troynewman.net> 
<mailto:troy at troynewman.net>
To: General pattern      discussion 
<mailto:nsrca-discussion at lists.nsrca.org> 
<mailto:nsrca-discussion at lists.nsrca.org>
Sent: Wednesday,      November 04, 2009 12:35 AM 
<mailto:nsrca-discussion at lists.nsrca.org>
Subject: Re:      [NSRCA-discussion] Looking For Props &  Header 
<mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
I      don’t believe there is such a prop made as the 18.1-11 Narrow. It 
doesn’t      exist. I may be wrong but I have been involved with running 
and testing the      APC props in the 18.1 series and WPN series.  There 
is a prop that is      designated as just 18-11 and this has a narrower 
blade than the      18.1-11.  The 18.1 series of props have a very wide 
blade. The 18-11 is      more like a 17-13 or 17-12 in terms of blade 
shape but its 18in dia and 11      pitch. 
<mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
I      know there is a 16.5-12 I just pulled one out in my box-o-props 
and it has a      profile like a narrow prop very similar to the 
17-10N
however it doesn’t      have the designation as 16.5-12 narrow. 
It’s just called the 16.5-12. If you      handed it to me with the name 
scratched off and said it was a 16.5-12 I      would have said it was a 
Narrow.  Same goes for the 18-11 regular it’s      a narrow essentially 
as well.  <mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
I      don’t know for sure why the “W” designation or the “N” for narrow 
is left      off of some props and added to others. I think it has a lot 
to do with the      equations and program that is used to create the 
prop profile.  <mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
To      sum up the props APC has the prop if it is or has been produced. 
I      don’t think Fred throws any of the molds away. So if a prop was 
produced at      one time it might be possible with some convincing to 
get some of them      produced again. I have been to the factory where 
the props are produced. It      amazing how they are produced, and the 
quantity and quality of props      produced for a given size. 
<mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
You      may not be asking for it by the proper name/designation
.the 
16.5-12 (is      actually like a narrow) and the 18-11 is like a narrow 
version of the      18.1-11  <mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
As      for Headers
..the new header is in testing and is performing 
well. The jury      is still out, we are working hard to insure the bugs 
are worked out. Right      things are going well and real progress has 
been made in the last couple      months. It will be sooner rather than 
later from the looks of things on the      new headers. 
<mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
I      hope this helps answer the questions 
<mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
Troy      Newman  <mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
 From: nsrca-discussion-bounces at lists.nsrca.org 
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of 
rjo626 at aol.com
Sent: Tuesday, November 03, 2009 8:20      PM
To: nsrca-discussion at lists.nsrca.org
Subject: [NSRCA-discussion] Looking For Props &  Header 
<mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
           Hello all! I'm looking for APC 18.1x11 narrow, and 16.5x12 
narrow.      Also,  <mailto:nsrca-discussion at lists.nsrca.org>
anyone      have a good NMP pattern header they're willing to part with 
/ sell? I've  <mailto:nsrca-discussion at lists.nsrca.org>
tried      Central Hobbies and APC with no luck. Thanks a      bunch! 
<mailto:nsrca-discussion at lists.nsrca.org>
    <mailto:nsrca-discussion at lists.nsrca.org>
           Later!  <mailto:nsrca-discussion at lists.nsrca.org>
                  RJO  <mailto:nsrca-discussion at lists.nsrca.org>
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